This weekend seems to be a bit quiter, than a usual summer weekend, but hopefully you will be able to find something exciting:
Colour! in The Ark - 15th July - 23rd August (Wednesday - Sunday)
http://ark.ie/events/view/colour
Summer in Dublin in Henry street - 25th July - 28rd August (Saturday)
http://www.dublintown.ie/whats-on-events/summer-dublin-events
Dublin Castle Sand Sculpture Exhibition - 3rd - 25th August
https://www.facebook.com/permalink.php?story_fbid=1028189160525781&id=621875627823805
The Big Grill Festival in Herbert Park - 13rd - 16th August
http://www.biggrillfestival.com/
Tallafest in Dublin 24 - 15th August
Drop-in Family Workshop in the National Gallery of Ireland - 15th August
Terenure Family Fun Day - 15th August
https://www.facebook.com/events/1618228381792494/
India Day in Phoenix Park 15th August
https://www.facebook.com/events/530143853804031/
LexIcon Family Day in Dun Laoghaire - 15th August
http://www.dlrevents.ie/lexicon.html
Summer at Farmleigh - 16th August
http://www.farmleigh.ie/events/Title,34470,en.html
War of the Beach Sculptures in Killiney beach - 16th August
http://events.dlrcoco.ie/event/biodiversity-events
Have Fun!